A man raises his hand up to the sky while praying at the Aurora Municipal Center during a vigil held for the victims killed by a gunman last Friday in the Century 16 movie theater in Aurora, Colorado, July 22, 2012.

James Holmes, the suspect in the shooting at a Colorado movie theater that left 12 people dead and 58 injured, is to appear in court for the first time as the prosecution begins in one of biggest US mass-murders in years.

Holmes, 24, is scheduled for a so-called advisement hearing at 9:30 a.m. local time at the courthouse in Centennial. He is suspected of firing into a crowded theater July 20 during an early morning showing of the new Batman movie. The prosecutor's office said it's considering pursuing the death penalty.

Holmes will be advised of his rights and no plea will be entered, said Casimir Spencer, a spokeswoman for the Arapahoe County District Attorney's Office. A judge will set the date for the formal filing of charges at the hearing, which may last only a few minutes. Holmes is being held at the Arapahoe County jail.

The rampage was the deadliest shooting in Colorado since the Columbine High School massacre in April 1999 and the worst mass shooting in the US since November 2009, when 13 people were killed at Fort Hood in Texas.

Sheriff's deputies today stood guard in front of the courthouse, a modest red-brick building fronted almost entirely by glass, as a stream of cars entered the parking lot. Police tape ringed the entrance to the grounds, where the national, state and county flags flew at half-staff.

Media tents

News media outlets from around the world set up tents in the parking lot to conduct interviews beneath the summer sun, while rows of satellite-television trucks vied for space. Reporters accosted people as they emerged from their cars and quizzed them about their connection to the massacre.

The gunman bought a ticket for "The Dark Knight Rises," entered the theater in the Denver suburb of Aurora and watched the film for a while before leaving, according to police. He went to a white Hyundai outside the building, put on a helmet and ballistic vest, armed himself and returned to the theater.

Police apprehended Holmes behind the theater, located in a shopping mall, after the first 911 call at 12:39 a.m. Three weapons were retrieved at the scene. A fourth, a .40-caliber Glock handgun, was found in Holmes's car. Over the weekend, police said they disabled explosive devices at Holmes's apartment.

Death penalty

Holmes, who had been a graduate student in neuroscience at the University of Colorado, Denver, doesn't have a criminal record, police said. Carol Chambers, the district attorney for Arapahoe County, said today that Holmes could face the death penalty. That decision would be made after consultation with the victims' families, Spencer, of the district attorney's office, said.

Capital cases are rare in Colorado, said Craig Silverman, a former prosecutor in the Denver District Attorney's Office now in private practice.

To seek the death penalty, prosecutors would need to establish one statutory aggravating factor, Silverman said. The case would qualify because it involves multiple victims, some of them children.

Three men are on the state's death row, according to the Colorado Department of Corrections website. The last person executed in the state was 53-year-old Gary Lee Davis in October 1997.

Chambers sought the death penalty against six defendants in four cases during a time when only one other capital case had been filed in the state, according to a 2010 profile by the Denver Post.

Premeditation

If the reported facts are accurate, the "evidence of premeditation would be overwhelming" against Holmes, said Sam Kamin, a law professor at Denver University. In Colorado, premeditation would be required to charge Holmes with multiple counts of first-degree murder, Kamin said in a phone interview.

The multiple weapons found, body armor and booby-trapping, "all of this shows it was more than a spur of the moment killing or series of killings," Kamin said.

In Colorado, an "aggravating factor" that may lead to a capital charge is if more than one person is killed in the same incident, Kamin said. In the theater-shooting case, another aggravating factor "is that the killings were heinous and cruel."

Holmes may present an insanity defense, requiring a determination that he suffers from a mental disease or defect rendering him unfit to stand trial, according to Kamin.

Public defender

He is to be represented initially by the local public defender office, which will be allowed to tour the site of the shooting tomorrow, police said at a July 21 press conference.

James O'Connor, head of the office, didn't return calls or e-mails seeking comment. Aurora Police Chief Dan Oates declined to comment on the possibility of an insanity claim.

Alternatively, Holmes's lawyers will search his personal history looking for "mitigating factors," or "what in his background or character mitigates the case in aggravation," Kamin said. Under such circumstances, the defendant may admit guilt and claim mitigating factors "not to spare him of conviction but to save his life," Kamin said.

The death toll in the shooting approaches the 15 killed in the 1999 massacre at Columbine High School in Littleton, about 20 miles (32 kilometers) from Aurora. The deadliest such incident in the US since then was the Virginia Tech rampage of April 2007 in Blacksburg, Virginia, in which Seung-Hui Cho took 33 lives, including his own.

Inevitable question

Prosecuting such crimes raises the inevitable question of the defendant's sanity, according to Richard Kornfeld, who represented the family of Columbine shooter Dylan Klebold. Any defense of Holmes would have to initially determine his mental state, Kornfeld, of Recht Kornfeld PC in Denver, said in a phone interview.

"Most people think an insanity defense is a hyper- technical cop-out, as if it existed in the law just to get around things," Kornfeld said. "The real analysis from the lawyer's perspective is: Can this person assist you in trying to help them?"